Protective effects of the Chinese prescription Hachimi-jio-gan against diabetic oxidative stress

We used rats with streptozotocin (STZ)-induced diabetes to investigate the effects of Hachimi-jioganon diabetic oxidative stress. Oral administration of Hachimi-jio-gan, at a dose of 50, 100 or 200 mg kg(-1) (body weight) daily, for 10 days to rats with STZ-induced diabetes resulted in significant dose-dependent decreases in serum levels of glucose and glycosylated protein, implying that Hachimi-jio-gan improves the abnormal glucose metabolism that leads to oxidative stress. Hachimi-jio-gan also showed a tendency to reduce the urine volume and significantly reduced the elevated urinary protein level. Moreover, rats with STZ-induced diabetes had high serum levels of superoxide and nitrite/nitrate. However, the administration of Hachimi-jio-gan dose-dependently reduced the overproduction of radicals associated with diabetes, suggesting the role of Hachimi-jio-gan as a radical scavenger that could protect against diabetic oxidative stress. Furthermore, thiobarbituric acid-reactive substance levels in serum and hepatic and renal mitochondria were dose-dependently lower in the Hachimi-jio-gan-treated groups than in the control diabetic group, which implies that Hachimi-jio-gan would alleviate the oxidative stress associated with diabetes through the inhibition of lipid peroxidation. These results indicate that Hachimi-jio-gan is a potential therapeutic agent that will reduce the damage caused by oxidative stress involved in diabetes.